When I try to run for example
optirun glxgears the glxgears window opens and closes immediately. It's the same for any other 3d-accelerated application.
optirun firefox or
optirun nautilus work though.
Strangely, everything was running fine until today. I didn't change anything, it just stopped working.
I'm running Ubuntu 13.10 with Linux-Kernel 3.13.0 on an MSI-GE40 Notebook with an nVidia GTX 760M graphics card with the "nvidia-331" driver and an Intel Core i7-4702MQ.